Cortical activation during rhythmic hand movements performed under three types of control: an fMRI study

Echoplanar fMRI was used to measure changes in cortical activation during the performance of a simple hand movement task under three types of voluntary control. Each of three imaging series alternated a task with rest: passive (in which the experimenter moved the hand), voluntary against low resistance, and voluntary against higher resistance. Contralateral activation was observed in the supplementary motor area (SMA), the primary motor cortex (M1), and the somatosensory cortex (S1) in all three tasks in each subject, whereas ipsilateral activation differed in each cortical region for each task. SMA had the widest prevalence of ipsilateral activation in all three tasks. In the M1, ipsilateral activation was observed in all but 1 subject in the two voluntary tasks but in only a few subjects in the S1 in any of the tasks. Quantitative changes in signal intensity and spatial extent of activation differentiated the voluntary tasks from the passive task and were most pronounced in the S1.     

The role of individual differences in the accuracy of confidence judgments

Generally, self-assessment of accuracy in the cognitive domain produces overconfidence, whereas self-assessment of visual perceptual judgments results in underconfidence. Despite contrary empirical evidence, in models attempting to explain those phenomena, individual differences have often been disregarded. The authors report on 2 studies in which that shortcoming was addressed. In Experiment 1, participants (N= 520) completed a large number of cognitive-ability tests. Results indicated that individual differences provide a meaningful source of overconfidence and that a metacognitive trait might mediate that effect. In further analysis, there was only a relatively small correlation between test accuracy and confidence bias. In Experiment 2 (N = 107 participants), both perceptual and cognitive ability tests were included, along with measures of personality. Results again indicated the presence of a confidence factor that transcended the nature of the testing vehicle. Furthermore, a small relationship was found between that factor and some self-reported personality measures. Thus, personality traits and cognitive ability appeared to play only a small role in determining the accuracy of self-assessment. Collectively, the present results suggest that there are multiple causes of miscalibration, which current models of over- and underconfidence fail to encompass.     

Nine, seven, five, or three: how many figures do we need for assessing body image?

320 Croatian female students (M=20.4 yr.) were recruited to examine the validity and reliability of figural scales using different numbers of stimuli (3, 5, 7, and 9) and different serial presentation (serial and nonserial order). A two-way analysis of variance (4 numbers x 2 orders of stimuli) was performed on ratings of current self-size and ideal size as dependent variables. Analysis indicated a significant main effect of number of stimuli. This, together with post hoc tests indicated that ratings were significantly different for a scale of three figures from scales of more figures, which in turn did not differ among themselves. Main effects of order of stimuli, as well as the interaction, were not significant. The results support the hypothesis that the optimal number of figures on a scale is seven plus (or minus) two.     

Aggressive and nonaggressive antisocial behavior in adolescence

This study examined whether a distinction between aggressive and nonaggressive antisocial behavior can be empirically verified in a large (254 girls and 254 boys) nonclinical (community) sample of Dutch adolescents between 12 and 18 years old. The results of confirmatory factor analysis for both boys and girls shows that aggressive and nonaggressive antisocial behaviors do not represent a single underlying dimension, but two separate constructs with moderate independence among them. These findings suggest that the conceptualization of adolescent antisocial behavior as a one-dimensional phenomenon is of questionable utility and supports growing evidence that aggressive antisocial behavior is distinct from other forms of antisocial behavior.     

A note on sequent calculi intermediate between LJ and LK

We prove that every finitely axiomatizable extension of Heyting's intuitionistic logic has a corresponding cut-free Gentzen-type formulation. It is shown how one can use this result to find the corresponding normalizable natural deduction system and to give a criterion for separability of considered logic. Obviously, the question how to obtain an effective definition of a sequent calculus which corresponds to a concrete logic remains a separate problem for every logic.     

An ethnomethodological clarification of Husserl's concepts of “regressive inquiry” and “Galilean physics” by means of discovering praxioms

This paper offers an ethnomethodological clarification of Husserl's concepts of Galilean physics and regressive inquiry. It employs the reader's textual-practical operationalization of these concepts. With the use of a simple optical prism as a perspicuous case of a scientific instrument, the reader will be asked and instructed to make a self-reflexive inquiry into the practical contingencies of the prismatic field of reflection. The reader will discover that the geometric structures of the reflective field of the prism is an achievement and formalization of the reader's own operatlonalizations. I named these discoverable discovering operationspraxioms or practical axioms — the pre-scientific contingencies of the geometric structures of prismatic reflection.I would like to thank Mike Lynch, Eric Livingston, George Psathas and Shelley Schweizer-Bjelic for their comments.     

Theories and inter‐theory relations in Bošković

During 1745–1755 Bo?kovi? explicitly used the concept of scientific theory in three cases: the theory of forces existing in nature, the theory of transformations of geometric loci, and the theory of infinitesimals. The theory first mentioned became the famous theory of natural philosophy in 1758, the second was published in the third volume of his mathematical textbook Elementorum Universae Matheseos (1754), and the third theory was never completed, though Bo?kovi? repeatedly announced it from 1741 on. The treatment of continuity and infinity in natural philosophy, geometry and infinitesimal analysis brought about inter‐theory relations in Bo?kovi?'s work during his Roman period. The two constructed theories of Bo?kovi?, the theory of forces and the theory of geometric transformations, directly influenced the idea for the construction of his third theory. These written theories refer to understanding and effective application of continuity and infinity in natural philosophy and geometry, and this task, according to Bo?kovi?, requires methodological support from the theory of infinitesimals.     

Differentiating myoclonus from tics

A Myoclonus Versus Tic Checklist facilitates making this vexing differential diagnosis. Although it appears to be a valuable tool for clinical, educational, and research purposes, psychometric characterization of the Myoclonus Versus Tic Checklist is needed.     

Versuche über die Grundlagen der räumlichen Orientierung bei der säugenden Ratte

Ohne ZusammenfassungDie Arbeit wurde in kürzerer Fassung am XVI. Internationalen Kongreß für Psychologie in Bonn 1960 unter dem Titel Räumliche Orientierung der gejungten Ratte vorgetragen.